Robotic Surgery System And Surgical Instrument

ABSTRACT

A robotic surgery system includes a robot and an instrument assembly. The instrument assembly includes a drive unit with at least one rotary drive having an electric motor and a drive shaft that has a coupling part for coupling to a drive shaft of the instrument; an instrument including an instrument shaft and a drive shaft that has a coupling part for coupling to a drive shaft of the drive unit; and an instrument interface including a sheath that encompasses the drive unit. In order to detachably couple an instrument module to an instrument part of a surgical instrument, an electromagnet in a magnet assembly of the instrument module is activated or deactivated, a permanent magnet of said magnet assembly is moved into a locking position and/or an angular position of a coupled counter element assembly of the instrument part is detected by an angle sensor of the instrument module.

CROSS-REFERENCE

This application is a continuation of International Patent ApplicationNo. PCT/EP2013/001253, filed Apr. 25, 2013 (pending), which claimspriority to DE 10 2012 008 537.0 filed Apr. 27, 2012, and DE 10 2013 004591.6 filed Mar. 15, 2013; and is related to U.S. patent applicationSer. No. 14/523,633 (pending), U.S. patent application Ser. No.14/523,713 (pending), and U.S. patent application Ser. No. 14/523,742(pending), each filed Oct. 24, 2014, the disclosures of which areincorporated by reference herein in their entirety.

TECHNICAL FIELD

The present invention relates to a robotic surgery system with a robotand an instrument assembly fastened thereat, such an instrument assemblycomprising a drive unit, an instrument, and an instrument interface. Theinvention also relates to a drive unit, an instrument, and an instrumentinterface for an instrument assembly, as well as a cover for theinstrument interface, and a method for their application.

BACKGROUND

Surgical instruments should be as sterile as possible. On the otherhand, robots are hard to sterilize, for example due to lubricants,abrasions, and the like.

Accordingly, a robot with an adapter socket is known from WO 2009/061915A2, with an adapter of a sterile cover being fastened thereat whichencompasses the robot. An instrument is fastened at the sterile side,facing away from the robot, with its end effector being actuated bypulleys inside the instrument shaft.

For this purpose, disks which are rotationally supported side-by-side inthe sterile adapter are coupled to counter disks, which are integratedin the robot arm. The rotary drives for actuating the counter disks arearranged in the robot base; the drive moments are transmitted viapulleys into the robot arm, so that the instrument, not having a driveof its own, can easily be manipulated.

SUMMARY

One objective of an aspect of the present invention is to provide animproved robotic surgery system.

Another aspect of the present invention relates to a surgicalinstrument, in particular a robot-guided one, comprising an instrumentpart, in particular an instrument shaft with an end effector, as well asan instrument module that can be coupled thereto in a detachablefashion, in particular a drive module for actuating the end effector, aswell as a method for coupling such an instrument part.

In minimally invasive surgery, a surgical instrument is guided through alocal opening into a patient. In particular when the instrument isguided by a robot, an end effector, for example a pair of scissors or anendoscopic optic, can be actuated inside the patient by anextracorporeal drive, for example an electric motor, for example pivotedand/or closed. In particular for the use of different end effectorsand/or in order to allow better fulfillment of the requirements forsterility during surgery, it is advantageous for the drive and the endeffector to be detachable from each other.

A surgical instrument with a drive module and an instrument shaft isknown from WO 2009/061915 A2. Rotary coupling elements of the drivemodule and rotational counter elements of the instrument shaft alignedthereto are coupled via sterile couplings in a form-fitting fashion,achieving an excellent alignment.

One objective of an aspect of the present invention is to improve thecoupling of an instrument part to an instrument module of a surgicalinstrument, in particular a robot-guided one.

Robotic Surgery System

A robotic surgery system according to one aspect of the presentinvention comprises one or more robots. In one embodiment, a robot mayhave six or more joints, in particular swivel joints, with more than sixjoints being able to allow an advantageous positioning of the redundantrobot. In one embodiment, the robot or robots have a control. Here,several robots may have a common central control or individual controls,which for a more compact illustration are also called jointly a controlof the robots. In one embodiment a robot may be arranged at a surgerytable, in particular in a detachable fashion.

One instrument assembly is fastened respectively at one or more robotsof the robotic surgery system according to one of the aspects of thepresent invention explained in the following. In one embodiment aninstrument assembly is fastened in a detachable fashion at a robot, inparticular in a form-fitting fashion, in a friction-fitting fashion,and/or magnetically, in particular electro-magnetically. In oneembodiment the instrument assembly, in particular a drive unit of theinstrument assembly, comprises a housing, which is fastened at anexterior of the robot, in particular a robotic (end or tool) flange,respectively, for example by way of a screwed, latched, or clampingconnection. Additionally or alternatively, an instrument interfaceand/or an instrument of the instrument assembly may be arranged inparticular at the exterior of the robot, in particular at a robot (endor tool) flange, respectively.

Instrument Assembly

An instrument assembly according to one aspect of the present inventionis implemented accordingly for the fastening at a robot and/or embodiedas a robot-guided instrument assembly. It comprises a drive unit, aninstrument, and an instrument interface according to one of the aspectsof the present invention explained in the following.

By the instrument assembly itself being equipped with a drive unit,preferably embodied overall in a mobile fashion, a transmission of driveforces from the robot itself to the instrument can be advantageouslyomitted, thus the robot can be designed with smaller dimensions, whichin particular can allow the cooperation of several slim robots within alimited operating space. Additionally, the drive unit can advantageouslybe adjusted easily to different instruments or exchanged as well. It ispreferably embodied as an independent module and/or one independent fromthe robot.

In one embodiment the instrument assembly comprises two or moredifferent drive units and/or two or more different instruments, whichoptionally can be connected like modules with an instrument and/or adrive unit to an instrument assembly fastened at the robot. Differentdrive units and/or instruments may in particular differ by the numberand/or capacity of actuated degrees of freedom. For example, a driveunit with three actuated degrees of freedom may optionally be connectedto an instrument with one or two actuated degrees of freedom and twoand/or one not-actuated one, i.e. unused and/or blind degree of freedom,and to instruments with three actuated degrees of freedom, which havedifferent end effectors.

The instrument and the drive unit are connected to each other in adetachable fashion, with an instrument interface being arranged betweenthe drive unit and the instrument. The instrument and the drive unit maybe fastened in particular in a form-fitting, friction-fitting,material-to-material, and/or magnetic fashion, preferably anelectromagnetic one, to each other and/or to an instrument interfacearranged between them. In particular, the instrument interface can bescrewed, latched, clamped, or also adhered to the drive unit and/or theinstrument, with the adhesion site being embodied as a predeterminedseparation point. Additionally or alternatively the drive unit may bescrewed, latched, or clamped to the instrument. In one embodiment theinstrument interface comprises an inherently stable flange for fasteningthe drive unit and/or the instrument. In one embodiment the drive unitis arranged at a proximal end and/or one distanced from theend-effector.

Drive Unit

A drive unit according to one aspect of the present invention comprisesone or more, in particular three or four rotary drives with respectivelyat least one drive shaft each. In one embodiment one or more rotarydrives of the drive unit comprise respectively one or more electricmotors each, in particular direct current or alternating current motors,having a stator and a rotor. Additionally or alternatively one or morerotary drives of the drive unit may have one or more hydraulic motorsand/or Piezo-drives each, which respectively move drive shaft(s) and/orcan apply a torque thereupon. The drive shaft can in particularrepresent a rotor and/or runner of an electric and/or hydraulic motor.In one embodiment the rotary drive comprises a rotary drive, preferablya coaxial transmission, in particular an epicyclic gear, preferably aplanetary gear or a harmonic-drive transmission, with the drive shaftrepresenting a driven and/or output shaft of the transmission. Inanother embodiment a rotary drive is embodied as a direct drive. In thepresent invention it is in particular understood that the drive shaft isdirectly impinged by an in particular hydraulically, electrically,and/or (electro)magnetically generated drive moment without anyinterposed transmission. In particular, such a direct drive can bedesigned without any independent self-inhibition in one embodiment. Thisway, advantageously the instrument with the drive unit flange connectedthereto can be removed from the patient. Additionally or alternatively arotary drive may comprise a sensor, in particular a coaxial one, inparticular a rotation and/or torque sensor arranged at the drivingand/or the driven side.

The drive shaft comprises a coupling part for coupling to a drive shaftof the instrument, which is connected in a torque-proof fashion to thedrive shaft. In one embodiment it may be designed axially-fixed to thedrive shaft, in particular integrated with this. In another embodimentthe coupling part is arranged in an axially displaceable fashion at thedrive shaft, in particular in a form-fitting fashion, in particular viaa fitting key, a helical gearing, a geared or polygonal shaft profile orthe like. In one further development the coupling part is axiallypre-stressed, in particular by means of a spring, against the instrumentinterface fastened at the drive unit or the instrument fastened at thedrive unit. This way, in particular any axial play can be compensatedand/or a compression force can be generated for a friction-fittingconnection.

In one embodiment, one or more drive shafts are embodied as hollowshafts. In one embodiment the drive unit includes one or more driveshafts, each arranged concentrically and/or coaxially inside a hollowdrive shaft surrounding it, in particular supported by it. Here, for amore compact illustration, the drive shaft which is arranged insideanother drive shaft is respectively called the inner drive shaft, theother drive shaft is called the outer drive shaft. For example, if inone embodiment the drive unit comprises three drive shafts, here theinnermost drive shaft, which may also be embodied as the hollow driveshaft, an inner drive shaft, a central drive shaft surrounding it, anouter drive shaft, and simultaneously another inner drive shaft, theoutermost drive shaft surrounding it, another drive shaft.Simultaneously the drive unit may also include four or more concentrichollow drive shafts.

In one embodiment one or more rotary drives are arranged coaxially inreference to their respective drive shaft, in particular in reference toa common rotary axis of coaxial drive shafts. In particular, one or morerotary drives may be arranged aligned behind each other. Similarly, oneor more rotary drives may be arranged parallel and offset in the radialand/or the circumferential direction in reference to their drive shafts,in particular in reference to a common rotary axis of coaxial driveshafts, and coupled therewith in particular via a spur gear or frictiontransmission. Simultaneously one or more rotary drives may be arrangedat an angle, in particular a right angle, in reference to theirrespective drive shaft, in particular a common rotary axis of coaxialdrive shafts, and coupled therewith in particular via a worm, helical,or crown-gear transmission.

A drive unit may respectively be connected wirelessly or in a wiredfashion to an energy source and/or the controls. In one embodiment thecover of the instrument interface explained in the followingencompasses, at least partially, also an energy and/or signal line ofthe drive unit.

Instrument

An instrument according to one aspect of the present invention comprisesan instrument shaft, with an end effector comprising one or more partspotentially being arranged at its distal end and/or the end facing awayfrom the drive unit, in particular a scalpel, a pair of pliers and/orlegs of scissors, or the like.

In one embodiment the instrument represents an endo-surgical and/orminimally invasive surgical instrument (“MIC”), in particular anendoscopic one, such as a laparoscopic or thoracoscopic one. Inparticular, the instrument shaft may be provided and/or embodied for thepurpose to be inserted into the patient through an access, which is inparticular equivalent essentially to the exterior diameter of theinstrument shaft, in particular via a trocar, and actuated there.

The end effector may have one or more degrees of freedom. In particularone or more parts of the end effector may have one or two degrees ofrotary freedom about an axis of rotation each, which are preferablyaligned perpendicularly in reference to the axis of the shaft. Forexample, a two-part end effector may represent a pair of pliers and/orscissors, with their legs pivoting about the same rotary axis inopposite directions.

In order to actuate the end effector, the instrument comprises one ormore drive shafts, in particular a drive shaft for actuating everydegree of freedom, in one embodiment therefore in particular one, two,or three drive shafts.

The drive shaft comprises a coupling part for coupling to a drive shaftof the drive unit, which is torque-proof in reference to the driveshaft. In one embodiment it may be designed axially fixed with the driveshaft, in particular integrated therewith. In another embodiment thecoupling part is arranged axially displaceably at the drive shaft, inparticular in a form-fitting fashion, for example via a fitted key, ahelical gearing, a toothed or polygonal shaft profile, or the like. In afurther development the coupling part is axially pre-stressed, inparticular by spring means, against the instrument interface fastened atthe instrument or the drive unit fastened at the instrument.

In one embodiment one or more drive shafts are embodied as hollowshafts. In one embodiment the drive unit comprises one or more driveshafts, which are respectively arranged concentrically and/or coaxiallyinside a driving hollow shaft surrounding it, in particular supportingit.

By the (innermost) drive shaft of the instrument being embodied as adriving hollow shaft, in one embodiment the insertion and/or passage ofan auxiliary instrument is advantageously enabled.

In one embodiment drive shafts of the drive unit and the instrument,coupled to each other, are aligned to each other. In one embodiment thedrive shaft(s) is/are coaxially arranged in particular aligned or offsetparallel in reference to the instrument shaft. This way, in oneembodiment a radially compact design can be achieved. In anotherembodiment the drive shaft(s) is/are arranged in an angular fashion, inparticular perpendicularly in reference to the instrument shaft. Thisway, in one embodiment the drive unit can be arranged in an angularfashion, in particular perpendicularly in reference to the instrumentshaft.

In one embodiment the instrument comprises a transmission at theinstrument side for converting a rotation of one or more drive shaftsinto a respective translation of one or more tensile and/or thrustmeans. A tensile means may in particular comprise one or more, inparticular opposite rope, belt, or tape drums, a tensile and/or thrustmeans, one or more tensile and/or thrust rods, in particular oppositeones.

In one embodiment the transmission comprises respectively one guide bar,in particular for one or more drive shafts of the drive unit each.According to one embodiment, a guide bar comprises a sliding sheath,which is supported torque-proof in reference to the instrument shaft andis axially displaceable, in particular at the instrument shaft or asurrounding hollow drive shaft. A guide bar and/or groove is embodied inone sliding sheath and the drive shaft, inclined in particular inreference to the axial direction, in which a fitting element, inparticular a feather key, is guided in a form-fitting fashion by theother sliding sheath and the drive shaft. This way a rotation of thedrive shaft is converted into an axial translation of the slidingsheath, which this way can in particular actuate a tensile and/or thrustmeans.

When in one embodiment a drive shaft is supported in a hollow driveshaft, in a further development a sliding sheath of a guide bar coupledto a drive shaft can simultaneously form a radial bearing, in particulara movable bearing, between it and an adjacent drive shaft. A fixedbearing of a drive shaft is preferably arranged at an end of theinstrument shaft facing the drive unit and/or at the proximal end.

In one embodiment the transmission is arranged in one half of theinstrument shaft facing the drive unit and/or the proximal side. Inanother embodiment the transmission is arranged in one half of theinstrument shaft facing away from the drive unit and/or the distal side.This way, the actuation can be advantageously transmitted over a largearea of the instrument shaft by the tensile and/or thrust means and/orby the drive shafts.

Auxiliary Instrument

According to one aspect of the present invention, an instrument assemblycomprises an auxiliary instrument, which, in particular in a detachablefashion, can be guided into and/or through the instrument of theinstrument assembly, in particular a guiding tube of the instrument, inparticular with a radial play or with a radial fitting. For thispurpose, in one embodiment the auxiliary instrument is designed in atubular fashion and may be stiff or flexible. According to oneembodiment the instrument may have a guiding tube, in particular a stiffone, in particular a central one, in which the instrument shaft isarranged and/or in which it can extend, at least essentially, over theentire interior length of the instrument shaft. In a further developmentan (innermost) hollow drive shaft of the instrument may act as theguiding tube and/or form a guiding tube.

In one embodiment the auxiliary instrument may be embodied as a guidefor gaseous and/or liquid media, in particular as a suction and/orsupply passage, and/or as an electric and/or light-wave conductor, inorder to conduct for example rinsing or surgical water-jet media to bedrained and/or supplied in particular at a vacuum or pressure, conductlaser and/or illuminating light and/or power into the patient, and/or toguide optic and/or electric signals out of said patient.

In one embodiment the auxiliary instrument may be inserted through theinstrument at a side of the instrument interface pointing away from thedrive unit, so that it is advantageously not necessary to isolate itfrom the drive unit in a sterile fashion. In another embodiment theauxiliary instrument is inserted through the drive unit, in particularan (innermost) hollow drive shaft of the drive unit.

In addition to the auxiliary instrument or alternatively thereto, adrive means for an actuation of an end effector may be inserted, inparticular in a detachable fashion, through the instrument of theinstrument assembly, in particular an (innermost) hollow drive shaft ofthe instrument, in particular inserted with a radial play or a radialfitting. For this purpose, in one embodiment the drive means may beembodied in a tubular fashion and be stiff or flexible. The drive meansmay in particular have one or more tensile and/or thrust means and/orone or more rotary shafts.

Instrument Interface

An instrument interface according to one aspect of the present inventioncomprises a drive unit, in particular a cover encompassing it in ahermetically and/or sterile fashion. In one embodiment the cover isflexible, in particular like a film. In one embodiment the cover issterile or can be sterilized at the exterior side facing way from thedrive unit.

This way, the drive unit, which due to abrasion, lubricants,temperature, and/or moisture-sensitive components or the like can onlybe sterilized with difficulty, can be isolated from the surgeryenvironment in a sterile fashion, with the actuation being transmittedthrough and/or via the interface into the instrument, whichadvantageously also can be sterilized.

In one embodiment, coupling parts of one or more drive shafts of thedrive unit and corresponding, in particular coaxial drive shafts of theinstrument are coupled to each other in a magnetic fashion. Inparticular in this case the instrument interface can be formed by asimple film, with preferably an air gap being formed between thecoupling parts, coupled to each other in a magnetic fashion.

In one embodiment the instrument interface comprises one or more rotaryintermediate elements, which are implemented to be coupled to onecoupling part of a drive shaft of the drive unit and one coupling partof a drive shaft of the instrument each, in particular in afriction-fitting or form-fitting fashion, when the interface is arrangedbetween the drive unit and the instrument, in particular fastened at thedrive unit and/or the instrument.

The assembly of the intermediate elements is preferably equivalent tothe assembly of the drive shafts and/or their coupling parts. Thus, ifin one embodiment the drive shafts of the drive unit and/or theinstrument are concentric, in particular the intermediate elements arealso arranged concentrically in reference to each other, withpreferably, as explained above, respectively one inner intermediateelement, in particular an annular one, is arranged concentrically in anouter annular intermediate element, in particular supported here. In onefurther development the intermediate elements are supported in a sealingfashion, for example by bearing rings, which include labyrinth seals orthe like. Sealed is understood in the present case in particular assterile in the medical sense, in particular sealed such that solid,preferably also liquid, in particular also gaseous elements of apredetermined size can overcome the seal at the most in a predeterminedmaximum quantity and/or rate, which may also tend towards zero.

The instrument interface may have an inherently stable flange forfastening the drive unit and/or the instrument, in which theintermediate elements are rotationally supported, in particular in asealed fashion.

Intermediate elements and coupling parts of the drive unit and/or theinstrument may have contact surfaces for a friction-fitting coupling,which contact each other when the instrument interface is arrangedbetween the drive unit and the instrument, and the instrument and thedrive unit are directly connected and/or connected via the instrumentinterface. For a form-fitting coupling, such contact surfaces mayinclude projections and recesses engaging each other and/orcomplementary steps. In particular, one or more projections and/or stepsmay be arranged at a coupling part and the intermediate part, whichengage in a form-fitting fashion the recesses and/or complementary stepsin the respectively other coupling part and intermediate element, whenthe instrument interface, in particular an inherently stable flange ofthe instrument interface, is arranged at the drive unit and/or theinstrument.

Preferably the coupling part and the intermediate element may includespur gearing, in particular Hirth-gearing engaging each other.

In one embodiment the friction-fitting or form-fitting contact areas maybe designed conically. This way, advantageously a self-centering and/orin particular in a combination with axially displaceable, preferablypre-stressed coupling parts, a compensation of an axial tolerance can beyielded.

In one embodiment the cover comprises an inner passage for an auxiliaryinstrument inserted through the instrument and the drive unit of theinstrument assembly. This inner passage may be embodied in a tubularfashion and pass an inner(most) hollow drive shaft of the drive unit. Ina further development it is sealed, in particular connected in a rotaryfashion to an inner(most) intermediate element of the instrumentinterface coupled to the hollow drive shaft.

In a further development the inner passage comprises a blind plug and acap ring. In an initial and/or assembly state the blind plug is fastenedat one end of the inner passage, closes it, and covers a circumferentialsection of the inner passage. The blind plug can then be pulled throughthe drive unit so that it projects from an outlet opening of the coverand can be removed. Subsequently the cap ring can be fastened at thecircumferential section of the inner passage, which is released byremoving the blind plug, and additionally closes the outlet opening ofthe cover. This way, a torus-shaped cover can be provided with a sterileexterior surface, with the drive unit being arranged in its annularspace and being isolated in a sterile fashion from the surgeryenvironment, and with the openings of its passage being available forinserting the auxiliary instrument.

The above-described further development is in particular suitable forthe above-explained drive unit with a hollow drive shaft. It can also beused for covering a robot with a tool flange comprising a hollow shaft,in particular in a sterile fashion. A (sterile) covering is inparticular understood in the present case as a partially or entirelyclosed and/or closed at all sides, in particular hermetically, coveringand/or encompassing.

According to one aspect of the present invention the cover, which mayinclude in particular one or more features of the above-described coverof the instrument interface, therefore comprises generally a tubularinner passage for guiding a robot or an above-described drive unitthrough the hollow shaft and through an outlet opening of the cover,with the inner passage comprising a blind plug and a cap ring,comprising one or more parts, for fastening at the outlet opening and ain particular exterior circumferential and/or jacket area of the innerpassage, which is released by removing the blind plug. The inner passagemay in particular be supported rotationally at the cover or be embodiedintegrally therewith. It may in particular be embodied stiffly orflexibly. For a more compact illustration even a stiff tubular innerpassage is generally characterized as tubular.

For encompassing the robot or the drive unit, initially the innerpassage provided with the blind plug is guided through the hollow shaftand the outlet opening of the cover.

The blind plug, which preferably has a closed exterior face and/or atubular jacket, prevents any soiling of the interior of the tubularinner passage and the circumferential area of the inner passage coveredby it. Similarly, the inner passage may initially be closed at its face,with the closed section subsequently being severed. In order tofacilitate the passage the blind plug may include a stiff and/orflexible insertion aid, in particular a string or a rod.

Subsequently the blind plug is removed and the cap ring is fastened atthe circumferential section of the inner passage, which was released bythe removal of the blind plug. As described above, the cap ring, whichmay be embodied stiffly or flexibly, in a further development can befastened at the outlet opening of the cover and close it, except for theinner passage. A part of the cap ring fastened at the circumferentialsection of the inner passage may be supported, in particular in a rotaryfashion, at one part of the cap ring fastened at the outlet opening ofthe cover or be embodied integrally therewith and/or in one piecetherewith.

The circumferential section of the inner passage, which was released bythe removal of the blind plug, was protected by the blind plug fromsoiling during the insertion process. A fastening at the circumferentialsection is in particular understood in the present case as a fasteningsuch that the circumferential section is covered partially or entirelyby the cap ring, seen in the longitudinal direction of the innerpassage. The circumferential section, which was released by the removalof the blind plug, may project beyond the cap ring in the longitudinaldirection at one or both sides. Similarly, except for thecircumferential section which was released by the removal of the blindplug or also a part of this circumferential section, the cap ring mayalso cover a circumferential section of the inner passage whichpreviously was not covered by the cap ring.

According to one aspect of the present invention, a surgical instrumentcomprises an instrument module and an instrument that can be detachablyconnected thereto, in particular a connected one. The surgicalinstrument may in particular be robot-guided and/or the instrumentmodule or the instrument part may have an in particular electro-mechanicinterface for an in particular mechanical and/or signal-technologicalfastening at a robot. According to one aspect, a robot is protected witha robot-guided surgical instrument. In one embodiment the surgicalinstrument is a minimally-invasive instrument, which is provided and/orembodied for the partial insertion into a patient through a so-calledtrocar opening.

In one embodiment the instrument module comprises an instrument shaftthat can be inserted into the patient with an end effector, with theinstrument part, that can be connected thereto in a detachable fashion,comprising a drive for actuating the end effector. Simultaneously, theinstrument module may also include a drive for actuating an end effectorof an instrument shaft of the instrument part that can be inserted intoa patient. For a more compact illustration, in the present casegenerally an instrument module and instrument part is being discussedwhich may respectively be embodied as a drive module and/or an endeffector module and/or an end effector part.

The end effector may in particular represent a scalpel, a probe,scissors, pliers, or a clamp, an optic for transmitting and/or receivingelectro-magnetic radiation and/or a fluid opening for inserting and/orsuctioning out gas and/or liquids. An actuation of the end effector mayin particular include the pivoting of the end effector about one, two,or three axes in reference to the instrument shaft and/or representingan actuation, in particular an opening and/or closing of the endeffector. The drive may also include one or more electric motors.Additionally or alternatively the drive may also include one or moremanual elements, in particular handles and/or wheels, for a manualactuation of the end effector. In general the drive may be implementedfor an electromotive, electromagnetic, pneumatic, hydraulic, and/ormanual actuation of the end effector.

In order to transmit a motion and/or force between the drive and the endeffector, with an anti-parallel pair of forces (e.g. a torque) perhapsgenerally representing any force in the sense of the present invention,the instrument module includes a coupling element assembly with one ormore coupling elements, the instrument part that can be connectedthereto in a detachable fashion comprising a counter element assemblywith one or more counter elements for coupling the coupling elementassembly.

In one embodiment, one or more coupling elements and the counter elementor elements that are or can be coupled thereto are be actuated in atranslational, mobile fashion, respectively by a degree of freedom ofthe end effector. In particular, such coupling elements can be guided ina displaceable fashion in a slide-bearing of the instrument module,preferably in a torque-proof fashion, in particular embodied as atappet. Additionally or alternatively, one or more coupling elements andthe counter element or elements that can be or is/are coupled theretoare be rotationally mobile in order to respectively actuate a degree offreedom of the end effector. In particular, such coupling elements maybe rotationally guided in a rotary bearing of the instrument module, inparticular in an axially fixed fashion, in particular embodied as ashaft.

According to one aspect of the present invention, one or more, inparticular all coupling elements of the coupling element assembly, canbe or are magnetically coupled to the counter element assembly and/orits counter element(s). For this purpose, in one embodiment the couplingelement or elements of the coupling element assembly of the instrumentmodule each includes a magnetic assembly for the magnetic coupling ofthe counter element of the counter element assembly. The counter elementor elements of the instrument part comprise(s) in one embodimentaccordingly a section that can be magnetically impinged. A section thatcan be magnetically impinged is understood in particular as a sectioncomprising a material which has a permeability value and/or a relativepermeability μ_(r) which amounts to at least 10, in particular a sectioncomprising a ferromagnetic or permanently magnetic material.

Via the magnetic coupling of the coupling assembly and counter elementassembly, the drive can advantageously be effectively and detachablyconnected to the end effector, in particular in a simple, sterile,and/or reliable fashion. Here, in one embodiment the magnetic assemblycan be arranged at the driving side and/or the instrument module may beembodied as a drive module. This way, in particular the instrument partwith the instrument shaft and/or the end effector can be embodiedeasier, more compact, and/or cheaper, in particular as a disposablearticle, and/or have or obtain better abilities for sterilization.Simultaneously, the magnetic assembly may also be arranged at the sideof the end effector and/or the instrument module may comprise theinstrument shaft and the end effector.

In one embodiment the magnetic assembly of one or more coupling elementsmay include one or more permanent and/or long-lasting magnets.

In one embodiment the permanent magnet or magnets is/are sizedmagnetically such that they securely couple the respective counterelement when it is adjacent to said coupling element; however, by anappropriately greater disassembly force it/they can be decoupledtherefrom, in particular by way of distancing the coupling and thecounter element from each other.

Preferably, however, one coupling and one counter element may bedecoupled from each other without being distanced from each other.

For this purpose the magnetic assembly of one or more coupling elementscomprises in one embodiment one or more electric magnets, which can beand/or is/are optionally electrified, in particular by a control meansembodied for this purpose, which can be in particular implemented in adrive control of the instrument.

By an optionally electrified electromagnet, in one embodiment acurrentless opened coupling between the coupling element and the counterelement and/or a so-called noncurrent principle may be provided. Thiscan preferably allow the instrument module and/or the instrument partand/or the drive and the end effector to become currentless and thus beseparated reliably in order to allow manually removing the end effectorout of the patient, even in case of a defect.

Simultaneously, in one embodiment a currentless closed coupling may beprovided between the coupling element and the counter element and/or aso-called operating current principle by an optionally electrifiedelectro magnet. This may preferably allow to also reliably couple theinstrument module and the instrument part and/or the drive and the endeffector, even in case of a power outage.

In one embodiment a magnetic assembly is provided for this purpose withone or more optionally electrified electromagnets as well as one or morepermanent magnets opposite thereto. A permanent magnet opposite theelectromagnet is understood in the present case in particular as apermanent magnet whose magnetic field is weakened by the electrifiedelectromagnet in the coupling area of the coupling element and thecounter element, in particular at least essentially compensated and/orneutralized. If this weakening and/or compensation is omitted fornon-electrified electromagnets, the then un-weakened and/oruncompensated permanent magnet couples the coupling element and thecounter element.

In one embodiment additionally or alternatively a magnetic assembly mayhave both one or more optionally electrified electromagnets as well asone or more permanent magnets operating in the same direction. In thepresent case, a permanent magnet operating in the same direction as anelectromagnet is understood as a permanent magnet whose magnetic fieldis amplified by the electrified electromagnet in a coupling section ofthe coupling element and the counter element. This way, the adhesionforce can be advantageously increased. In reference to a solutionwithout a permanent magnet, in one embodiment the electromagnetic fluxrequired for transmitting force and thus the energy consumption and thegeneration of heat can be reduced. In reference to a solution without anelectromagnet, in one embodiment the permanent magnet may be reduced.Additionally or alternatively, in one embodiment one or more permanentmagnets of a magnetic assembly can be arranged at, particularly in, thecoupling element, adjustably between a locked and an unlocked positiondifferent therefrom, in particular supported in a displaceable and/orrotational fashion, and/or can be adjusted, in particular shifted and/ordisplaced. In a further development the permanent magnet or magnets areadjustable in an electromotive, hydraulic, pneumatic, and/or manualfashion. Additionally or alternatively the permanent magnet or magnetsmay be lockable in the locked, the unlocked, and/or in a positiondifferent from these two positions.

By removing a permanent magnet from the coupling area of the couplingelement and the counter element, in one embodiment the magnetic couplingof the coupling element and the counter element can be reduced by thispermanent magnet, and this way the coupling element and the counterelement can be decoupled. Additionally or alternatively, in oneembodiment the coupling element may include a magnetically conductivesection for coupling the counter element, which is magnetically impingedby a permanent magnet, at least essentially, only when it is in thelocked position and/or when it is magnetically separated from thepermanent magnet when it is in the unlocked position.

In general, in one embodiment the coupling element may comprise amagnetically conductive section for coupling the counter element, whichin particular optionally, preferably by way of electrifying and/ornon-electrifying at least one electromagnet and/or adjusting at leastone permanent magnet can be brought into the locked position, by whichthe magnetic arrangement can be and/or is impinged magnetically. Amagnetically conductive section is understood in the present case inparticular as a section comprising a material which has a permeabilityvalue and/or a relative permeability μ_(r) which amounts to at least 10,in particular a section comprising a ferromagnetic material. By moving apermanent magnet outside of the magnetic influence with the magneticallyconductive section of the coupling element the magnetic force applied bythe magnetically conductive section upon a counter element is weakened,in particular at least essentially eliminated, so that the magneticcoupling is released. This way, preferably an adjustment path for thedecoupling can be reduced by adjusting a permanent magnet into anunlocked position. In particular when in one embodiment a couplingelement includes a yoke comprising a magnetically conductive material,around which an optionally electrified coil is arranged, in oneembodiment generally a magnetic assembly may be formed integrally withthe coupling element, in particular an electromagnet.

In order to couple an instrument module and instrument part of asurgical instrument, according to one aspect of the present invention atleast one electromagnet of the magnetic assembly of the instrumentmodule is activated and/or electrified, and this way preferably acurrentless open coupling is closed between the coupling element and thecounter element. For the purpose of decoupling, the electromagnet isaccordingly deactivated and/or kept free from electricity.

Additionally or alternatively at least one permanent magnet of themagnetic assembly of the instrument module may be adjusted into thelocked position. For the purpose of decoupling the permanent magnet isaccordingly adjusted into the unlocked position.

In particular for the purpose of locking a currentless closed couplingbetween the coupling element and the counter element, in one embodimentfor the coupling of an instrument module and an instrument part of asurgical instrument at least one electromagnet of the magnetic assemblyof the instrument module, which additionally includes at least onepermanent magnet, is deactivated and/or deenergized. For the decoupling,the electromagnet is accordingly activated and/or electrified.

In one embodiment, the coupling element and the counter element and/orthe coupling element and the counter element assembly can be or areconnected, in addition to the magnetic coupling, in a form-fittingfashion, preferably in order to center them in reference to each otherand/or to fix them in a torque-proof fashion. In particular, either thecoupling element or the counter element may include at least oneeccentric projection, which engages a respective recess in the other onecoupling element of counter element or a sterile barrier arrangedbetween them, in particular a coupling part of such a barrier, when thecoupling element and the counter element, perhaps via a barrier, arecoupled to each other. The magnetic coupling can axially secure thisform-fitting connection in one embodiment.

Similarly, one of the coupling element and the counter element mayengage like a pin in a sheath section and/or socket section of the otherone of the coupling element and the counter element when the couplingelement and the counter element are coupled, with in particular thecoupling element engaging a sheath section and/or socket section of thecounter element or the counter element like a pin engaging a sheathsection and/or a socket section of the coupling element. This way, inone embodiment the coupling element and the counter element can be fixedin a form-fitting fashion perpendicular in reference to theirlongitudinal extension, with the magnetic coupling fixing them in thedirection of their longitudinal direction in a force-fitting fashion.

In one embodiment the instrument module and/or the instrument part canbe sterilized and/or they are sterile. In particular when the instrumentmodule and/or the instrument part comprise an electromotive drive foractuating an end effector of the instrument it may be difficult tosterilize it. Thus, in one embodiment, in particular a sterile barriermay be arranged and/or present between the coupling element assembly andthe counter element assembly. The sterile barrier may in particular beembodied in a flexible fashion, at least in the coupling section, inorder to allow following a motion of the coupling element and thecounter element for actuating the end effector under an elasticdeformation.

In one embodiment the sterile barrier comprises a coupling part for amagnetic coupling of a counter element to a coupling element. Thecoupling part may be connected in a mobile fashion via a seal to theremaining barrier, in particular a film, or be connected fixed thereto,in particular embodied in an integral fashion. This way a mechanicalforce transmission can be improved beyond the barrier. In one embodimentthe coupling part comprises a magnetically conductive material in orderto improve the magnetic coupling.

In particular when the coupling element and the counter element arecentered towards each other, in particular in a form-fitting fashion, itmay be advantageous for the coupling element and/or the counter elementto be supported with play in a guide of the instrument module and/or theinstrument part. This way the coupling element and/or the counterelement may compensate a certain lateral offset during the couplingprocess.

In one embodiment the coupling element and the counter element areembodied like tappets and/or shafts and coupled to each other abuttingand/or at their faces, with the magnetic assembly pulling the couplingelement and/or the counter element in the direction of their preferablyaligned longitudinal extension towards each other, in order to transmittensile forces and/or torque.

In one embodiment of the present invention the coupling element and thecounter element assembly may be advantageously coupled to each other ina sterile, compact fashion and/or at least essentially without play andslippage and/or without any visual control, and/or decoupled from eachother.

In particular when a coupling element and a counter element are coupledto each other magnetically in a torque-proof fashion, this may result,in particular without any additional form-fitting connections or in caseof ambivalent form-fitting connections, such as via a Hirth-gear, thatthe angular position of the counter element in reference to theinstrument module is not unambiguously known after the coupling process.However, this is mandatory in minimally invasive robotic surgery, inwhich the intra-corporeal end effector is precisely actuated by theextracorporeal drive.

Thus, according to one aspect of the present invention, which preferablycan also be combined with the above-stated aspects, an instrument modulemay include a coupling element assembly with one or more rotationallysupported coupling elements which can be coupled detachably atrotationally supported counter elements of a counter element assembly ofan instrument part, by which an end effector of a surgical instrumentcan be actuated, which comprises the instrument module and theinstrument part coupled thereto.

In one embodiment the coupling element and the counter element(assembly) may be coupled and/or can be coupled to each other in aform-fitting fashion, in particular by way of gears, preferablyHirth-gears or spur-gears. If a sterile barrier is arranged between thecoupling element and the counter element assembly, in one embodiment thecoupling element and the counter element (assembly) may be coupledand/or can be coupled in a form-fitting fashion to a coupling part whichpreferably is supported rotationally in said barrier.

In general, the coupling element and the counter element (assembly)according to this aspect of the present invention can be coupled to eachother in two or more different alignments, with in the present case inparticular a rotary orientation and/or position between the couplingelement and the counter element about its rotary axis is considered theorientation. These orientations may represent discrete orientations. Ina simple case, one of a coupling element and a counter element shows oneor more projections which may engage respective recesses in at least twoorientations between the coupling element and the counter element in theother one of the coupling element and the counter element. Similarly,the coupling element and the counter element may include correspondinggears, which engage gears offset by the respective orientation, and thisway can couple the coupling element and the counter element. Thedifferent orientations may also be geometrically undetermined and/orarbitrary, for example by an electromagnet being activated in a couplingelement and a ferromagnetic section of the counter element, fixing it inthis orientation with its plane face contacting the plane face of thecoupling element in an arbitrary orientation.

In particular in order to allow in such couplings, which are possible inseveral orientations between the coupling element and the counterelement, actuating the end-effector via the drive, preferably withoutprior calibration, the instrument module includes in one embodiment anangle sensor for detecting the angular position of the coupled counterelement assembly, in particular a transmitter, in particular in one ormore counter elements. The angle sensor may have several individualsensors each for detecting an angular position of a coupled counterelement. The counter element or elements of the counter element assemblyinclude respectively appropriate torque-proof transmitters, which areimplemented to be detected by the angle sensor of the instrument module,in particular an individual sensor.

For a more compact illustration, in the present case the multitude ofangular positions of two or more, in particular of all counter elementsof the counter element assembly, is generally called an angular positionof the counter element assembly in the sense of the present invention.An angular position of this counter element may in particular representan orientation and/or rotary position of this counter element inreference to the instrument module, in particular in reference to apoint fixed at the housing or the rotary bearing. Similarly, an angularposition of a counter element may represent an orientation and/or rotaryposition of this counter element in reference to the coupling elementcoupled thereto.

In one embodiment the angle sensor is implemented to detect, in additionto an orientation and/or rotary position of the coupling element coupledto the counter element in reference to the instrument module, inparticular in reference to a point fixed at the housing and/or therotary bearing. In one further development, from this information, inparticular by an addition of the correct algebraic sign, with theangular position of the counter element in reference to the couplingelement coupled thereto, the angular position of the counter element canbe determined in reference to a point fixed at the housing and/or therotary bearing. Similarly, from the angular position of the counterelement in reference to a point fixed at the housing or the rotarybearing, inversely the angular position of the counter element can bedetected and/or determined in reference to the coupling element coupledthereto.

The angle sensor may be implemented for a touch-less detection of theangular position of the counter element assembly and/or the angularposition(s) of the transmitter and/or the transmitters. In particular itmay represent a magnetic, electric, capacitive, and/or optic anglesensor. The transmitter or transmitters, with its/their north-south axispreferably at least essentially being oriented perpendicular inreference to the rotary axis of the counter element, may include atransponder, preferably a RFID-system, an optic marking, or the like.

In one embodiment, the angle sensor is embodied as an absolute valuetransmitter and/or embodied to detect an absolute angular position ofthe counter element assembly in reference to the instrument moduleand/or the coupling element, for example via an absolute-codedtransmitter or receiver. The coding may have an angular range of 360°(so-called single-turn absolute value transmitter) so that the anglesensor reads two angular positions, distorted by 360°, as the sameangular position. In another embodiment the coding may have an angularrange of more than 360° (so-called multi-turn absolute valuetransmitter) so that the angle sensor detects two angular positionsdistorted by 360° as different angular positions.

Preferably the angular position is available in an absolute valuetransmitter directly after the coupling and detecting of the anglesensor without any distortion of the counter element assembly beingrequired.

In another embodiment the angle sensor is embodied as an incrementalvalue transmitter and/or for the purpose of only detecting an angularchange of the counter element assembly in reference to the instrumentmodule and/or the coupling element. In a further development thetransmitter or receiver is distance-coded or has one or more referencemarks. Upon crossing a reference mark, the angular position can then bedetected by integrating and/or adding the incremental values and/orangular changes.

In one embodiment a surgical instrument comprises several instrumentparts, which can optionally be coupled to the instrument module, withthe counter element assemblies of the different instrument parts havedifferently coded transmitters, which are implemented to be detected bythe angle sensor of the instrument module, with the angle sensoradditionally being implemented to detect the coding of the transmitterand this way identify the coupled instrument part. This way, thefunctionalities can determine on the one hand the orientation of thecounter element assembly and on the other hand identify the instrumentpart coupled thereto, by which the transmitter or transmitters and theangle sensors is/are implemented. In one embodiment a permanent magnetcan also serve or be used as a transmitter for detecting the angularposition and for the magnetic coupling.

During or after the coupling of the instrument part to the instrumentmodule in one of multiple orientations, according to one aspect of thepresent invention, the angular position of the coupled counter elementassembly of the instrument part is detected, in particular in referenceto the coupling element assembly or a point fixed at the housing of theinstrument module, using the angle sensor of the instrument module. Thisway, after the detection, the orientation of the counter element orelements, and thus preferably also a position and/or coordinate of theend effector are known, so that in one embodiment the end effector canbe correctly actuated by a drive without recalibration.

In one embodiment, a context, in particular a calibration offset betweenthe angular position of the counter element assembly and an end effectorposition, is detected in advance and saved. After coupling the counterelement assembly the end-effector position can be determined from theangular position of the counter element assembly, detected by the anglesensor, in consideration of said context.

BRIEF DESCRIPTION OF THE DRAWINGS

Additional advantages and features are discernible from the dependentclaims and the exemplary embodiments. For this purpose it is shown,partially schematically:

FIG. 1 a part of an instrument assembly of a robotic surgery systemaccording to an embodiment of the invention in a perspectivecross-section,

FIG. 2 a transmission at the side of the instrument according to anotherembodiment of the present invention;

FIG. 3 a transmission of FIG. 2 in another perspective cross-section;

FIG. 4 a cross-section of a conical coupling of an instrument assemblyaccording to one embodiment of the present invention;

FIGS. 5A-5D additional embodiments of such a conical coupling;

FIG. 6 another shaft coupling of an instrument assembly according to anembodiment of the present invention;

FIG. 7 a cross-section of this shaft coupling of FIG. 6;

FIG. 8 a magnetic coupling of an instrument assembly according to oneembodiment of the present invention;

FIG. 9 the magnetic coupling of FIG. 8 in a cross-section;

FIGS. 10A, 10B a transmission according to one embodiment of the presentinvention in two perspective views;

FIG. 11 an enlarged cross-section of the transmission of FIGS. 10A, 10B;

FIGS. 12A, 12B an instrument according to one embodiment of the presentinvention with a distal transmission in a perspective overall view (FIG.12A) and/or an enlarged detail (FIG. 12B);

FIG. 13 an instrument interface according to one embodiment of thepresent invention;

FIG. 14 the instrument interface of FIG. 13 with a connected blind plug;

FIG. 15 the instrument interface of FIG. 14 with the blind plug removed;

FIG. 16 the instrument interface of FIG. 15 with the cap ring connected;

FIG. 17 the instrument interface of FIG. 16 with the instrument coupled;

FIG. 18 an instrument assembly with an inserted auxiliary instrumentaccording to an embodiment of the present invention;

FIG. 19 a part of an instrument of an instrument assembly according toanother embodiment of the present invention;

FIG. 20 a part of an instrument of an instrument assembly according toanother embodiment of the present invention;

FIGS. 21A, 21B: an encompassing of a robot with a cover according to oneembodiment of the present invention;

FIG. 22 a part of a surgical instrument according to one embodiment ofthe present invention in a longitudinal cross-section;

FIG. 23 a part of a surgical instrument according to another embodimentof the present invention in an illustration according to FIG. 1

FIG. 24 a part of a surgical instrument according to another embodimentof the present invention shown in FIG. 1, 2 in a respectiveillustration;

FIG. 25 a part of a surgical instrument according to another embodimentof the present invention; and

FIG. 26 a part of a surgical instrument according to another embodimentof the present invention shown to FIG. 4 in a respective illustration.

DETAILED DESCRIPTION

FIG. 1 shows a part of an instrument assembly of a robotic surgerysystem according to one embodiment of the invention in a perspectivecross-section.

The instrument assembly comprises an instrument 1, a drive unit 2connected thereto, and an instrument interface with a sterile cover 5arranged between the drive unit and the instrument.

In this exemplary embodiment the rotary axes of the drive unit coincidewith a shaft axis of the instrument. This concept is in particularsuitable for instruments actuated with tensile/thrust rods.

The sterile surgical instrument 1 is shown in FIG. 1 at the left side,the drive unit 2 in FIG. 1 at the right side. The instrument 1 ismechanically attached in a detachable fashion to a housing 6 of thedrive unit 2 via a connection flange 4 at a proximal end of theinstrument shaft 3. The drive unit 2 is encompassed by a sterile cover 5in order to prevent any contamination of the surgery area.

In this exemplary embodiment, three independent rotary drives arerespectively located in the housing 6 of the drive unit 2, eachcomprising a drive shaft 10, 13, and/or 15 and a correspondingelectromotor 7, 8, and/or 9. The drive shafts 10, 13, 15 are embodied ashollow shafts and arranged coaxially in reference to each other. Thedrive shaft 10 is supported entirely at a bearing site 11 in the housing6. The inner drive shaft 13 is supported with a bearing 12 in the driveshaft 10, the drive shaft 15 with a bearing 14 in the drive shaft 13.This concept advantageously allows, primarily in the radial direction, avery compact design of the detachable instrument interface. Thus, in amulti-robot application the risk of collisions between individual robotscan be considerably reduced due to the shorter allowable minimumdistance between the instruments.

The symbolic illustrations of the electric motors 7, 8, 9 includeadditional components required for a regular operation, such astransmissions and/or sensors, for example. Preferred embodiments areconcentrically arranged motor units, which can be implemented either asdirect drives or as motors with reduction gears arranged downstream, forexample planetary gears or harmonic-drive gears.

In a modification, not shown, the rotary drives may be radially offsetelectric motors, which respectively drive the drive shafts with a spurgear or friction wheel drive, or have orthogonally offset electricmotors, which drive the drive shafts respectively with a worm drive,helical drive, or crown wheel gears.

The nested drive shafts 10, 13, and 15 are continued at the instrumentside in the form of drive shafts 16, 17, and/or 18, which are alsoembodied as hollow shafts and which are arranged coaxially in referenceto each other. The support of the drive shafts 16, 17, and 18 at theinstrument side is embodied as fixed/floating bearings 28, 29, 30,arranged at the proximal end of the instrument shaft 3. The shaft 16 isradially and axially supported at the bearing site 28 in the instrumentshaft 3. The interior drive shaft 17 is supported with the bearing 29 inthe drive shaft 16, the drive shaft 18 with the bearing 30 in the shaft17. The sliding sheaths 23, 24, and 25 act as loose bearings, whichsimultaneously are components of a transmission 22 at the instrumentside for the conversion of the rotational drive motion into atranslational motion of the tensile and/or thrust means 26, 39 and/or 40(cf. FIGS. 10A, 10B). They finally transmit the drive motion to theinstruments and/or end effector degrees of freedom at the distal end ofthe instrument shaft 3.

FIG. 1 shows as an example only one tensile and/or thrust means 26,although for each degree of freedom of the instrument a separatetransmission link being provided. Examples for such tensile and/orthrust means are pulleys, Bowden-pulleys, or tensile/thrust rods.

In order to connect the drive shafts 10, 13, and 15 of the drive unit tothe drive shafts 16, 17, and 18 at the instrument side a couplingmechanism is provided, which simultaneously represents a sterile barrierbetween the instrument and the non-sterile drive unit. The couplingshown as an example in FIG. 1 is a conical coupling, which transmits thedrive moments via friction-fitting or form-fitting means.

By this design principle the drive shafts 15 and 18, located inside inthe coaxial arrangement, can be embodied as hollow shafts as well. Thisway sufficient space remains in the center of the instrument shaft 3 inorder to guide additional drive means, for example a Bowden pulley, arotary shaft with an elastic section in the area of the multiple link todrive an end effector, and/or an auxiliary instrument, in particular anelectric line, a hose, or the like. Another potential application ofthis design principle is the insertion of special surgical instrumentsthrough the center of the instrument shaft.

In order to ensure the sterility of the elements guided through thecenter of the instrument even in the area of the drive unit 2, thesterile barrier with an inner passage in the form of a sterile guidingtube 27 also extends through the entire drive unit 2, as described inthe following.

FIG. 2 shows a transmission 100 at the instrument side according toanother embodiment of the present invention, in which the axes of thedrive shaft and the shaft are orthogonal. This arrangement is inparticular suitable for instruments which are actuated with pulleys.However, it can also be used for instruments with tensile/thrust rods,in which the transmission at the instrument side can be realized for thetransmission of the rotation of a drive shaft into a translation of atension and/or thrust means, for example as a push-crank mechanism.

A housing 104 is located at the proximal end of the instrument 101,connected fixed to the instrument shaft 103. The instrument 101 isconnected at the proximal end via a sterile barrier 105 to the driveunit 102 (with its housing not being shown). The drive shafts 106, 107,and 108 are coaxially arranged in the drive unit 102 in order to achievedimensions as compact as possible. They are continued at the instrumentside respectively as a pulley 109, 110, and/or 111. The connection ofthe shaft sections respectively occurs via the sterile intermediatecoupling sections 116, 117, and 118, which are rotational in referenceto each other.

An intermediate coupling element 118 of the exterior drive shaft 106 isconnected to the sterile barrier 105 and rotationally supported therein.In the exemplary embodiment the drive shafts of the drive unit and theinstrument are coupled in a form-fitting fashion to a sprocket coupling,which is described in greater detail with reference to FIG. 6.

The pulleys 112, 113, and 114 actuating the degrees of freedom of theinstrument are wound about the pulleys and/or drive shafts 109, 110,and/or 111 at the instrument side, so that the force flux is closedbetween the drive shafts 106, 107, and 108 and the degrees of freedom ofthe instrument. Optionally, a tubular passage 115 may be provided, whichfor example can be used for guiding an auxiliary instrument, inparticular a media line, to the distal end of the instrument shaft 103.

Detachable coupling with sterile barriers for at least one rotary drivetrain

In order to connect the instrument to the drive unit, a simple,detachable coupling mechanism is provided, which simultaneouslyrepresents the sterile barrier between the instrument and the unsteriledrive unit.

FIG. 4 shows in a cross-section the conical coupling of the exemplaryembodiment of FIG. 1 with a sterile barrier. The coupling assemblytransmits the drive moments from the drive shafts 10, 13, and 15 by wayof friction-fitting or form-fitting means to the drive shafts 16, 17,and 18 at the instrument side. At the proximal ends of the hollow shafts16, 17, and 18 at the instrument side, coupling parts are arranged inthe form of exterior cones 34, 35, and 36, which are connected fixed tothe respective hollow shaft. At the distal ends of the drive shafts 10,13, and 15 the coupling parts 31, 32, 33 are arranged with inner cones.The connection of the ends of the shaft occurs via conical intermediateelements 19, 20, and/or 21, which act as sterile barriers. Theseelements are connected to each other and also to the sterile barrier 5in a sealed fashion. These connections only serve for the simplehandling during the installation of the sterile barrier; however, theyallow otherwise all motions required for moving the intermediateelements, in particular a rotation of the drive shafts. Simultaneouslythese intermediate elements 19, 20, and/or 21 represent a gap sealand/or labyrinth seal between the coupling parts.

The coupling parts 31, 32, 33 arranged at the drive shafts 10, 13, and15 are each connected to a shaft in a torque-proof, however axiallydisplaceable fashion, for example by a geared or a polygonal shaftprofile. This way, the axial pre-tension required for transmitting forcecan be applied by springs, for example, acting upon the coupling partsat the driving side. Simultaneously, a potential axial offset iscompensated of the shaft sections between the drive side and theinstrument side.

Instead of the combination of the inner cones at the driving side andthe outer cones at the instrument side, for each pairing an inner and anouter drive shaft of the drive unit and the instrument is possible andadditional arrangements as well, which are sketched in FIGS. 5A-5Daccording to the following configurations:

Coupling part 31/32/33, 34/35/36 FIG. 5A FIG. 5B FIG. 5C FIG. 5D Innerhollow drive shaft Inner cone Outer cone Inner cone Outer cone of thedrive unit Inner hollow drive shaft Inner cone Outer cone Inner coneOuter cone of the instrument Outer hollow drive shaft Outer cone Innercone Inner cone Outer cone of the drive unit Outer hollow drive shaftOuter cone Inner cone Inner cone Outer cone of the instrument

FIG. 6 shows a shaft coupling with a sterile barrier, which transmitsthe drive moments in a form-fitting fashion via the spur gears, forexample a Hirth-gear, from the drive shafts 10, 13, and 15 to the driveshafts 16, 18 at the instrument side, FIG. 7 shows a cross-section ofthis shaft coupling. Instead of the conical coupling of FIG. 4, 5, inparticular the shaft coupling can be provided in an instrument assemblyaccording to FIG. 1, 2 or 3.

For this purpose, at the proximal coupling parts of the hollow shafts16, 17, and 18 at the instrument side spur gears 203, 204, 205 areapplied, which are connected fixed to the respective hollow shaft. Atthe distal ends of the drive shafts 10, 13, 15, the coupling parts arearranged in the form of sliding sheaths with spur gears 200, 201, 202.The connection of the shaft ends occurs via sheath-like intermediateelements 206, 207, and 208 with spur gears at both sides, which act assterile barriers. The intermediate sheaths 206, 207, 208 are connectedto each other and to the sterile barrier 5 by the fastening rings 209,210, 211. The inner passage and/or the sterile guide tube 27 areconnected this way to the innermost intermediate sheath 208 so that theentire arrangement represents a sterile barrier with gap seals. Theintermediate sheaths 206, 207, 208 only serve for the simple handlingduring the installation of the sterile barrier, however otherwise theyallow all motions required for the function. They act as gap and/orlabyrinth seals.

The sliding sheaths 200, 201, 202 arranged on the drive shafts 10, 13,and 15 are each connected to the shafts in a torque-proof yet axiallydisplaceable fashion, for example by a geared or polygonal shaftprofile. This way the axial pre-stressing necessary for transmittingforce can be applied for example by springs which act upon the slidingsheaths 200, 201, 202. Simultaneously a potential axial offset iscompensated between the shaft sections at the drive side and theinstrument side.

Another variant of the shaft coupling with sterile barriers is themagnetic coupling shown in FIG. 8. The shaft coupling may be providedinstead of the conical and/or shaft coupling of FIGS. 4 to 7, inparticular in an instrument assembly according to FIG. 1, 2 or 3.

Coupling parts in the form of magnetic rings 200, 201, and/or 202 arefixed at the distal ends of the drive shafts 10, 13, and 15. Similarthereto, coupling parts are fixed in the form of magnetic rings 203,204, and/or 205 at the hollow shafts 16, 17, and 18 respectively at theinstrument side. All magnetic rings 200 to 205 are sectionallymagnetized and aligned towards each other with a preferably small axialdistance and/or air gap in order to allow transmitting the highestpossible drive moments. The strength of the moment that can betransmitted depends, in addition to the air gap, also on the magneticfield strength and the number of magnetic sectors.

FIG. 9 shows in a cross-section a magnetic coupling with sterilebarriers. The magnetic rings are aligned towards each other with minimalaxial distance in order to allow transmitting the highest possible drivemoments. An advantageous feature of this coupling principle is thesimple design of the sterile cover 5. Due to the narrow axial air gap ofthe magnetic coupling a simple film can be used and no specially formedpart is necessary.

Implementing the Rotation-Translation Movement Type at the InstrumentSide

In one embodiment of the present invention only rotary drives are used.The drive trains in robotic guided surgical instruments however use, dueto the tight design space inside the instrument shaft, primarily pulleysor tension/thrust rods for transmitting the drive motions to the distalend of the instrument. Thus, according to the above-described detachableinstrument interface, a transmission 22 is provided at the instrumentside in order to convert the rotary drive motion into a translationalmotion of the pulleys or tension/thrust rods.

FIG. 10 shows in two perspective illustrations a converting transmission22 according to one embodiment of the present invention, in which aseparate sliding sheath is provided for each drive shaft. In the caseshown here, the three sliding sheaths 23, 24, and 25 convert therotation of the drive shafts 16, 17, and 18 into a translation of thetension and/or thrust means 26, 39, and 40. The sliding sheaths 23, 24and 25 act simultaneously as a distal loose bearing for the hollowshafts 16, 17, and/or 18. The sliding sheaths themselves only have atranslational degree of freedom, which allows the displacement along theaxis of the shaft. The restriction of the degree of freedom of thesliding sheaths 23, 24 and 25 is achieved by groove-guides 41, 42, and43, which are nested in each other. The sliding sheaths 23, 24, and 25are inserted into each other such that a sheath positioned outsideaccepts the bearing of the sheath located inside. This way, a verycompact design is achieved.

Accordingly, the exterior sliding sheath 23 is supported in theinstrument shaft 3. A transitional fitting between the sheath 23 and theshaft 3 serves as a radial bearing. A rotation of the sheath 23 isblocked by a feather key 41 fixed at the sheath 23, gliding in a grooveinserted in the instrument shaft 3. The sliding sheath 24 is supportedin the exterior sliding sheath 23. A transitional fitting between thesheath 24 and the sheath 25 serves as a radial bearing. A rotation ofthe sheath 24 is blocked by the groove guide 42. The inner slidingsheath 25 is supported in the sliding sheath 24. A transitional fittingbetween the sheath 25 and the sheath 24 serves as a radial bearing. Arotation of the sheath 25 is blocked by the groove guide 43.

The coupling of the drive shafts to the sliding sheaths is done with aguiding groove, with its functionality being explained as an examplewith reference to the hollow shaft 18 located at the inside, and FIG.11, which shows an enlarged cross-section. A helical groove 37 isinserted at the distal end of the hollow shaft 18. A pin 38, which isfixed at the sliding sheath 25, engages the helical groove 37 in aform-fitting fashion. Thus, a rotation of the hollow shaft 18 leads to adisplacement of the sheath 25 along the axis of the shaft and thus alsoto an adjustment motion of the tensile and/or the thrust means 26. Atthe distal end of the sliding sheaths 23, 24, and 25 the tensile and/orthrust means 26, 39, and 40 are connected, which transfer the drivemotion to the degrees of freedom of the instrument and/or anend-effector at the distal end of the instrument shaft 3.

One advantage of this solution is that the drive motions, in particularthe adjustment angle and the angular speed, can be adjusted within everyinstrument to the respective requirements, as the incline of the guidebar determines the transmission ratio and the operating range. Thus, thedrive unit can be used for the highest possible number of differentinstruments and the efficiency and user friendliness can be increased.

Instead of the proximal arrangement shown in FIGS. 10, 11, thetransmission can alternatively also be arranged at the distal end of theinstrument, thus as close as possible at the instrument kinematics andthe end effector. FIGS. 12A and 12B show an instrument 400 according toan embodiment of the present invention with a distal transmission in aperspective, comprehensive view (top in FIG. 12A) and/or an enlargeddetail (bottom in FIG. 12B).

The transmission is located at the distal end of the instrument 400 andthus near the instrument kinematics 402 and the end effector 403. Theactuation of the distal joint 402, which in the example shown isembodied as a parallel kinematics, occurs with tensile and/or thrustmeans in the form of coupling rods 408 and 409, which are rotationallyconnected to the segment carrying the end effector. The respectivelyother ends of the coupling rods 408 and 409 are rotationally connectedto the sliding sheath 406 and 407, which are displaced along the axis ofthe shaft for adjusting the angle of the joint. The sliding sheaths 406and 407 are connected to the hollow shafts 404 and/or 405, with theconversion of the rotary drive motion into the translational feed motionof the sheath occurring via the guide bar mechanics described inreference to FIGS. 10A, 10B, and 11. Sufficient space remains in thecenter of the inner hollow shaft 405 in order to pass drive meansthrough it, for example a Bowden pulley or a rotary shaft with aflexible section in the area of the multiple joint for driving the endeffector 403 and/or an auxiliary instrument, in particular electricsupply lines, hoses, or the like.

Contrary to the pulleys used in common instruments of minimally invasiverobotic surgery, in this embodiment the drive performance is transmittedfrom the drive unit to the tip of the instrument via hollow shafts,coaxial in reference to the shaft of the instrument. This can yield aconsiderably higher resilience and stiffness of the drive train inreference to pulleys or thin solid shafts, so that advantageously higherdriving forces can be transmitted. Accordingly this embodiment isespecially recommended for instruments in which higher processing forcesdevelop, e.g., devices for placing staple sutures.

Sterile barrier between the drive unit and the instrument Somecomponents of the drive unit cannot tolerate the environmentalconditions during a sterilization process. Accordingly, the instrumentinterface comprises a sterile cover which shields the drive unit duringoperation. In addition to the cover, which securely encompasses thehousing of the drive unit and commonly is embodied as a film hose, theinstrument interface between the drive unit and the instrument shouldallow the transmission of mechanic power and electric signals andsimultaneously prevent any contamination of the surgery area by anunsterile drive unit.

FIG. 13 shows an overview of the instrument interface 500 with variouspartial components, which may be provided for example for the instrumentassembly of FIG. 1.

The instrument interface 500 comprises a sterile film cover 501, whichencompasses the housing of the drive unit 2, an inherently stable flangeand/or instrument carrier 5, which for the purpose of coupling the drivetrains, comprises for example the conical intermediate elements 19, 20,21 described in reference to FIG. 4, as well as an inner passage in theform of the guiding tube 27. A connection ring 503 connects the guidetube 27 to the film cover 501. In order to ensure the sterility of theguide tube 27 during the insertion process into the drive unit 2 theguiding tube 27 is initially closed at its proximal end with a blindplug 502, which also covers a section of the jacket. The instrumentinterface 500 is designed as a comprehensive assembly, in which allparts are combined to form a unit. This way the handling is greatlysimplified. In case of the magnetic coupling explained in reference toFIG. 8, a film is sufficient as a sterile barrier and/or instrumentinterface between the shaft sections.

The other FIGS. 14 to 17 illustrate the sterile packaging of the driveunit and the connection of a surgical instrument thereto. The instrumentcarrier 5 is placed onto the drive unit as the first step (cf. FIG. 14).Simultaneously the sterile guide tube 27 is inserted into the hollowshaft as well as the intermediate parts 19, 20, 21 of the shaftcouplings into the drive unit 2, and the film cover is slid over thedrive unit 2. Then the blind plug 502, which after passing through thesterile guide tube 27 has become unsterile due to the hollow shaft ofthe drive unit 2, is pulled off the guiding tube 27 and discarded by anunsterile member of the surgery team (cf. FIG. 15). Due to the fact thatthe blind plug 502 also covers a portion of the jacket of the guidingtube 27, the section of the guiding tube 27 projecting out of the driveunit 2 remains sterile. Finally, the sterile cover is sealed by aplacement of the cap ring 503 onto the guiding tube 27 (cf. FIG. 16).FIG. 17 finally shows the docking of a surgical instrument 1 to thesterilely packaged drive unit 2.

Guiding Additional Drive Trains and/or Auxiliary Instruments Through theInstrument Shaft Towards the Distal End of the Instrument

In addition to a simple mechanic design of the detachable instrumentinterface, the coaxial arrangement of all drive shafts offers theadvantage that the center of the drive unit and the instrument are clearfor additional driving means, for example pulleys, Bowden pulleys,and/or rotary shafts being guided through it to actuate the endeffector. For example, a Bowden pulley can be used in duplicate; thecover serves for transmitting a first actuating force, the core of thetransmission. Additionally, electric lines for monopolar or bipolarinstruments, suction and rinsing hoses may be guided in the center ofthe instrument shaft. Similarly, other auxiliary instruments may also beguided by the robot, for example fiber optics for laser applications orflexible instruments for the argon-plasma coagulation, for cryosurgery,or water jet surgery, frequently used for tumor resection.

FIG. 18 shows an instrument assembly with a stiff or flexible auxiliaryinstrument being inserted and/or guided through.

For this purpose, after the placement of the sterile cover 501, theauxiliary instrument 504 is advanced from the rear through the guidingtube 27 through the drive unit 2 to the distal end of the instrument 1and fixed in this position. Subsequently, the auxiliary instrument 504can be used like a common robot-guided instrument and be moved by thedegree of freedom provided by the instrument 1 in the surgery area. Inaddition to the suitability for stiff and flexible auxiliary instrumentsthis solution offers the advantage that no additional design space isrequired in the area of the detachable instrument interface in order toinsert the auxiliary instrument 504 into the instrument shaft.

FIG. 19 shows a part of an instrument of an instrument assemblyaccording to another embodiment of the present invention which is inparticular suitable for flexible auxiliary instruments. Here, theauxiliary instrument 507 is not introduced through the drive unit 2, butthrough a curved tubular section 506, which is arranged at theinstrument shaft 505 directly in front of the drive unit 2 and/or theinstrument interface. In this solution a sterile cover 501 can bedesigned in a simpler fashion, because the auxiliary instrument 507 isnot guided from the rear through the drive unit.

FIG. 20 shows a part of an instrument of an instrument assemblyaccording to another embodiment of the present invention in which theaxis of the drive and the axis of the shaft are orthogonal. Here, bothstiff as well as flexible auxiliary instruments can be inserted and/orpassed through. The auxiliary instrument 508 is fed from the rearthrough a guiding tube 115 and through the housing 104 to the distal endof the instrument shaft 103 and fixed. Subsequently, the auxiliaryinstrument 508 can be used like a common robot-guided instrument andmoved with the degrees of freedom provided by the instrument 100 in thesurgery area. Here, too, no design space is required at the proximal endof the instrument shaft in order to insert the auxiliary instrument 508.

The drive unit provides the mechanic drive capacity for all activedegrees of freedom of the surgical instrument. It is located at theproximal end of the instrument and is designed as an independent modulewhich is suitable to drive different instruments. In order to avoid anycontamination of the surgery area the drive unit is hermetically sealedwith a sterile protective cover.

The detachable instrument interface is located between the drive unitand the surgical instrument. Its primary purpose is the mechanicalconnection of the surgical instrument to the drive unit. On the one handit provides a force flux between the drive and instrument functionalunits, and ensures a precise and repeatable relative positioning andfixation of these units. In order to transmit the required mechanicalpower to the instrument, the detachable instrument interfaceadditionally comprises detachable couplings, which generate the forceflux between the individual drives in the drive unit and the drivetrains in the instrument. In order to ensure the sterility of thesurgical instrument under all circumstances, the detachable instrumentinterface acts simultaneously as a sterile barrier between the unsteriledrive unit and a sterile instrument.

Advantageously the coupling of a surgical instrument of an instrumentassembly according to one embodiment of the present invention is simpleand requires no detailed special professional knowledge in roboticsystems. The detachable instrument interface according to one embodimentadvantageously allows the repeatable and reliable coupling of theinstrument including all force transmission elements without any visualinspection. The interface can preferably transmit one or more drivemotions from a drive unit to a surgical instrument, while the sterilityat the instrument side can be ensured. The drive unit and/or thedetachable instrument interface advantageously require little structuralspace in order to minimize the risk of collision in case of a systemwith several robots, for example. In order to improve the performance ofa robotic guided instrument with regards to control technology thetransmission of mechanic drive energy to the surgical instrument shallbe embodied with as little play and slippage as possible.

FIGS. 21A, 21B show an enclosure of a robot with a cover according toone embodiment of the present invention. The robot, with its robotichand being partially indicated in FIGS. 21A, 21B comprises a hollowshaft. A tubular interior passage 27 of a cover 501 is guided throughit, which includes an outlet opening 507. The end of the inner passage27 guided through is covered at its beginning with a blind plug 502, forexample in a clamped fashion, which has a closed face and a tubularjacket, in order to protect the interior and a facial circumferentialsection of the inner passage 27 from soiling when being guided through.

The blind plug 502 is guided through the hollow shaft and the outletopening 507 (FIG. 21A) and subsequently removed. At the circumferentialsection of the inner passage 27, which was released thereby, and theedge of the outlet opening 507 a sterile cap ring 503A, 503B isfastened, once more for example in a clamping fashion (FIG. 21 B). Thisway, in a simple fashion a sterile encompassing of the robot can beprovided with the hollow shaft and/or simultaneously the drive unit ofan instrument assembly.

In the exemplary embodiment the inner passage 27 is supported with itsend (bottom in FIGS. 21A, 21B) opposite the blind plug 502 and/or thecap ring 503 at the cover 501 in a rotary fashion, for example asdescribed above with reference to the intermediate elements of theinstrument interface. The cap ring is embodied in two parts, with onepart 503A of the cap ring, fastened at the circumferential section ofthe inner passage, being supported rotationally at a part 503B of thecap ring fastened at the outlet opening of the cover. This way, theinner passage 27 in its entirety is supported rotationally at the cover501 and can be entrained, in particular with an auxiliary instrumentmoved by the hollow shaft. In a variant (not shown) the inner passagemay also be embodied integrally and/or in one piece with the coverand/or connected thereto via a one-piece cap ring, with it beingpossible to compensate any potential rotation of the hollow shaft, forexample by loose [sections] of the inner passage and/or the cover.

FIG. 22 shows a part of a minimally invasive surgical instrumentaccording to one embodiment of the present invention in a longitudinalcross-section with an instrument module 1 and a detachable instrumentpart 2 connected thereto.

The instrument part comprises an instrument shaft 22 with an endeffector (not shown), which can be inserted into a patient, with theinstrument module comprising a drive for actuating the end effector, aswell as an electro-mechanical interface for fastening at a robot (notshown).

The instrument module 1 comprises a coupling element assembly withseveral coupling elements in the form of translationally moved tappets10, which are guided in a sliding bearing 12 of the instrument module ina torque-proof but displaceable fashion, and with only one being shownin FIG. 22 for better visibility. The instrument part comprises arespective counter element assembly with counter elements in the form oftranslationally moved (counter) tappets 20, which are guided in asliding bearing of the instrument shaft 22 in a torque-proof butdisplaceable fashion in order to respectively actuate a degree offreedom of the end effector. The translational movement of the tappetsand counter-tappets in order to actuate an intra-corporeal degree offreedom of the minimally invasive instrument by the extra-corporealdrive is indicated in FIG. 22 by the double arrow of the motion.

The tappets 10 of the coupling element assembly can be magneticallycoupled with the counter-tappets 20 of the counter element assembly. Forthis purpose, the tappets 10 each include a magnetic assembly for amagnetic coupling of the opposite counter tappet 20, which has a section21 which can be magnetically impinged, comprising a ferromagnetic orpermanently magnetic material. The tappets 10 of the coupling elementassembly include a magnetically conductive section 11 made from aferromagnetic material, which has an exterior ring and a central yoke.

An electric coil is arranged about this yoke and cast with anon-magnetic casting material 13, in order to integrally form anelectromagnet 31 of the magnetic assembly with the tappet 10, which canoptionally be electrified and/or is electrified by a control meansprovided for this purpose, which is implemented in a drive control ofthe instrument (not shown).

Additionally, each magnetic assembly includes a permanent magnet 30,which is opposite the electromagnet 31, with its magnetic field being atleast essentially compensated by the electrified electromagnet 31 in afacial coupling area of the tappet and the counter-tappet.

Via the optionally electrifiable electromagnet 31 a current-free closedcoupling is provided between the coupling element and the counterelement; as long as the electromagnet 31 is current-free, the permanentmagnet 30 couples the section 21 of the counter tappet 20, which can beimpinged magnetically, in a secure fashion to the magneticallyconductive section 11 of the tappet 10. By electrifying theelectromagnet 31 it compensates the magnetic field of the permanentmagnet 30 in its facial coupling area to such an extent that theinstrument part 2 can be removed from the drive module 1, preferablyunder its own weight and/or minor manual force.

Similarly, the electrified electromagnet 31 and the permanent magnet 30may also act in the same direction and/or their magnetic fields mayamplify each other in a facial coupling area of the tappet and thecounter tappet.

Optionally a sterile barrier 40 is arranged between the coupling elementassembly and the counter element assembly, which is embodied like a filmand is flexible in the coupling area in order to follow under elasticdeformation any translational movement of the tappet 10 and the countertappet 20 in order to actuate the end s effector.

In one variant, not shown, the permanent magnet 30 may be omitted inorder to inversely provide a currentless open coupling between thecoupling element and the counter element by an optional electrifying ofthe electromagnet 31; as long as the electromagnet 31 is electrified, itcouples the section 21 of the counter tappet 20, which can be impingedmagnetically, in a secure fashion to the magnetically conductive section11 of the tappet 10. When the electromagnet 31 is currentless theinstrument part 2 can be removed from the drive module 1.

FIG. 23 shows a part of a minimally invasive surgical instrumentaccording to another embodiment of the present invention in anillustration according to FIG. 22. Equivalent elements are marked withidentical reference characters so that reference is made to the otherdescriptions, and in the following only the differences from theembodiment shown in FIG. 22 are discussed.

In the embodiment of FIG. 23 the magnetic assembly is not provided withan electromagnet but only with the permanent magnet 30. In particular inorder to decouple the coupling element from the counter element 10, 20without rendering them distant from each other, in this embodiment thepermanent magnet 30 can be displaced in the coupling element and/or thetappet 10 between the locked position shown in FIG. 23 and an unlockedposition distanced therefrom indicated in dot-dash lines in FIG. 23,which is indicated in FIG. 23 by a dot-dash double arrow showing themotion. The permanent magnet 30 is guided in a displaceable fashion in alongitudinal bore of the tappet 10 and can be adjusted for example by anelectromotive, hydraulic, pneumatic, and/or manual displacement of thethrust rod on which it is arranged, and locked in the locked and theunlocked position.

The facial, magnetically conductive section 11 of the tappet 10 is onlymagnetically impinged by the permanent magnet 30, at least essentially,when it is in the locked position. In the unlocked position (indicatedin dot-dash lines in FIG. 23) the permanent magnet 30 is howeverseparated from the magnetically conductive section 11 of the tappet 10and arranged in a magnetically non-conductive section of the tappet 10made from plastic with a permeability value μ_(r) which amounts tomaximally 2.

By adjusting the permanent magnet 30 in the bore of the tappet 10 intothe locked position, its magnetically conductive section 11 can beoptionally impinged magnetically by the magnetic assembly to couple thecounter tappet.

In the embodiment of FIG. 23 the optionally sterile barrier 40 comprisesa stiff coupling part 41 made from a magnetically conductive material,in order to improve the mechanic force transmission and the magneticcoupling. In one variant, not shown, the optional sterile barrier mayalso be embodied like a film, as in FIG. 22, and/or the optional barriermay include a coupling part as the embodiment of FIG. 22.

In the embodiment of FIG. 23, a part comprising a non-magnetic materialis marked 13. It may be designed as in the embodiment of FIG. 22 as acasting compound and thus it carries the same reference character.Similarly, the part 13 may be a molded part, which is fastened at themagnetically conductive section 11 and acts as a stop for thedisplaceable permanent magnet 30.

FIG. 24 shows a part of a minimally invasive surgical instrumentaccording to another embodiment of the present invention in anillustration according to FIGS. 22, 23. Equivalent elements are againmarked with identical reference characters so that reference is made tothe other description, and in the following only the differences fromthe embodiment of FIGS. 22, 23 are discussed. In particular, themagnetic assembly and the magnetically conductive sections are not shownin FIG. 24 for a better overview, they may in particular be embodied asshown in FIG. 22 or 23 and/or explained with reference thereto.

In the embodiment of FIG. 24, in addition to the magnetic coupling thetappet 10 and the counter tappet 20 can be connected and/or areconnected in a form-fitting fashion. For this purpose, the tappet 10engages a sheath and/or socket section of the counter tappet 20 like apin when the coupling element and the counter element are coupled toeach other. This way the coupling element and the counter element arefixed in a form-fitting fashion perpendicular in reference to theirvertical longitudinal extension, in FIG. 24, i.e. horizontal in thedrawing level and/or perpendicular in reference thereto, with themagnetic coupling fixates them in a force-fitting fashion in thedirection of their longitudinal extension.

The tappet 10 and the counter tappet 20 are thereby centered inreference to each other in a form-fitting fashion. In order tocompensate a lateral and/or angular offset the counter tappet 20 issupported in the embodiment of FIG. 24 with play in the sliding bearingof the instrument shaft 22.

In the embodiment of FIG. 24 the magnetically conductive section 21 ofthe counter tappet 20 is arranged inside the sheath and/or socketsection of the counter tappet 20 in order to this way preferably avoidany unintended magnetic interference.

In the embodiments explained, the coupling element and the counterelement are formed like tappets and coupled to each other abuttingand/or at their faces, with the magnetic assembly of the couplingelement and the counter element pulling them towards each other in thedirection of their longitudinal extension in order to transfer tensileforces, while pressures are transmitted in a form-fitting fashion.

Additionally or alternatively, coupling elements and counter elements10, 20 can be rotationally mobile in the embodiments in order torespectively actuate a degree of freedom of the end effector. Themagnetic assembly pulls the coupling element and the counter element inthe direction of their longitudinal direction towards each other inorder to allow a transmission of torque in one embodiment. This canoccur in a friction-fitting fashion due to the axial tension by themagnetic assembly. Equivalently, it may also occur in a form-fittingfashion. For this purpose, in a variant not shown the tappet 10 or thecounter tappet 20 may include one or more eccentric projections, inparticular gears, which engage respective recesses, in particularinverse gears in the counter tappets 20 and/or the tappet 10, when thecoupling element and the counter element are magnetically coupled toeach other. In one variant, not shown either, the tappet 10 or thecounter tappet 20 includes Hirth-gears.

In such a case, the coupling part 41 may in particular be connected viaa rotary seal in a rotational fashion to the remaining barrier 40.Similarly the coupling part 41 can be connected via a translational sealto the remaining barrier 40 in a displaceable fashion, as respectivelyindicated in FIG. 24.

FIGS. 25, 26 respectively show a part of a minimally invasive surgicalinstrument according to another embodiment of the present invention in alongitudinal cross-section with an instrument module 1 and a detachableinstrument part 2 connected thereto. Equivalent elements are once moremarked with identical reference characters so that reference is made tothe above-stated description, and in the following only the differencesfrom the embodiment of FIGS. 22-24 are discussed.

In the embodiment of FIG. 26 a coupling element in the form of arotationally supported drive shaft 10 of an electric motor of the drive(not shown) and a counter element in the form of a rotationallysupported drive shaft 20, supported parallel and offset in referencethereto, of an effector of the instrument (not shown) can be coupled toeach other in a form-fitting fashion by mutually engaging spur gears 14,24. In the embodiment of FIG. 25 a sterile barrier 40 is arrangedbetween the coupling assembly and the counter element assembly with arotationally supported coupling part 42 having two spur gears, whichengage the spur gears 14 and/or 24 and this way also couple the couplingelement and the counter element 10, 20 in a form-fitting fashion.

A rotary bearing and/or a housing of the instrument module 1 and/or theinstrument part 2 are indicated with 12 and/or 22 respectively.

In a variant, not shown, the coupling element and the counter element10, 20 may additionally or alternatively be magnetically coupled to eachother in a torque-proof fashion, as explained above with reference toFIGS. 22-24.

The spur gears between the spur wheels 14, 24 and perhaps 42 areambivalent and/or can be coupled in various orientations, offset inreference to each other by the tooth pitch.

In order to nevertheless be able to actuate the end effector by a drivewithout any prior recalibration, the instrument module 1 includes in theembodiments of FIGS. 25, 26 a touchless angle sensor in the form of amagnetic encoder for detecting the angular position of the coupled driveshaft 20 in reference to the housing and/or the rotary bearing 12 of theinstrument module 1. The drive shaft 20 comprises accordingly atorque-proof transmitter in the form of a permanent bar magnet 51, whichis embodied to be detected by the angle sensor 50. The north-south axisof the bar magnet 51 is aligned perpendicular in reference to the axisof rotation of the drive shaft 20.

During or after the coupling of the instrument part 2 to the instrumentmodule 1 in one or more alignments, the angular position of thetransmitter 51 is detected in the coupled drive shaft 20, which in FIGS.25, 26 once more is only shown as an example, in reference to a pointfixed at the housing of the instrument module by the angle sensor 50 ofthe instrument module. This way, after the detection of the orientationof the counter elements, a position of the end effector is also known,so that the end effector can be correctly actuated by a drive withoutrecalibration.

While the present invention has been illustrated by a description ofvarious embodiments, and while these embodiments have been described inconsiderable detail, it is not intended to restrict or in any way limitthe scope of the appended claims to such detail. The various featuresshown and described herein may be used alone or in any combination.Additional advantages and modifications will readily appear to thoseskilled in the art. The invention in its broader aspects is thereforenot limited to the specific details, representative apparatus andmethod, and illustrative example shown and described. Accordingly,departures may be made from such details without departing from thespirit and scope of the general inventive concept.

LIST OF REFERENCE CHARACTERS

In the FIGS. 1 to 21:

-   1, 100, 101, 400 Instrument-   2, 102 Drive unit-   4 Connection flange-   3, 103, 505 Instrument shaft-   5, 105, 501 (Sterile) cover-   6, 104 Housing-   7, 8, 9 Electric motor-   11, 12, 14, 28, 29, 30 Bearing site-   19, 20, 21, 206, 207, 208 Intermediate element-   22 Transmission-   23, 24, 25, 37, 38, 200, 201, 202, Sliding sheath (guide bar)-   406, 407-   26, 39, 40 Tensile/thrust means-   31-36, 200-205, 300-305 Spur gearing (coupling part)-   27, 115 (Sterile) guide tube-   37 Helical groove-   38 Pin-   41, 42, 43 Groove guide-   10, 13, 15, 16, 17, 18, Drive shaft-   106, 107, 108, 109, 110, 111,-   404, 405, 406-   402 Instrument kinetics-   403 End effector-   408, 409 Coupling rod-   100 Transmission at the instrument side-   112, 113, 114 Pulleys-   115 Guide tube-   116, 117, 118 Intermediate coupling segment-   209, 210, 211 Fastening ring-   500 Instrument interface-   501 (Sterile) film cover-   502 Blind plug-   503 Cap ring-   504, 507, 508 Auxiliary instrument-   506 Tubular section-   507 Outlet opening

In the FIGS. 22 to 26:

-   1 Instrument module-   10 Tappet; shaft (coupling element)-   11 Magnetically conducting section-   12 Housing of the instrument module, sliding/rotary bearing-   13 Casting compound, form part/component-   14 Spur wheel-   2 Instrument part-   20 Tappet, shaft (counter element)-   21 Section that can be magnetically impinged-   22 Instrument shaft, sliding/rotary bearing-   24 Spur wheel-   30 Permanent magnet-   31 Electromagnet-   40 Sterile barrier-   41, 42 Coupling part-   50 Angle sensor-   51 Permanent bar magnet (transmitter)

What is claimed is:
 1. A robotic surgery system with a robot; and aninstrument assembly, in particular one detachably fastened at the robot.2. An instrument assembly for an in particular detachable fastening atthe robot of a robotic surgery system according to claim 1, with: adrive unit (2; 102); an instrument (1; 100; 400) which is detachablyconnected to the drive unit; and an instrument interface (5, 500), whichis arranged between the drive unit and the instrument. 3-5. (canceled)6. A drive unit (2; 102) for an instrument assembly according to claim2, comprising at least one rotary drive (7, 8, 9) with a drive shaft, inparticular a hollow drive shaft (10, 13, 15; 106, 107, 108), with acoupling part (31, 32, 33; 200, 201, 202; 300, 301, 302) for coupling toa drive shaft of the instrument. 7-17. (canceled)
 18. A cover with atubular inner passage for guiding through a hollow shaft of a robot or adrive unit according to claim 6 and through an outlet opening (507) ofthe cover, characterized in that the inner passage comprises a blindplug (502) and a cap ring (503) for fastening at a circumferentialsection of the inner passage, which is released by removing the blindplug.
 19. A method for encompassing the robot or a drive unit accordingto claim 6 with a cover according to the previous claim, characterizedin that the inner passage, provided with a blind plug (502), is guidedthrough a hollow shaft and the outlet opening of the cover, issubsequently removed, and the cap ring (503) is fastened at thecircumferential section of the inner passage, which has been released bythe removal of the blind plug. 20-34. (canceled)